Make conduit certificate readonly and select-on-click

Summary: See comments in https://secure.phabricator.com/D6331#comment-3 -- make the Conduit Token and Conduit Certificate interfaces readonly and select-on-click.

Test Plan:

• Viewed /conduit/token/, verified it was readonly and selected on click.
• Viewed /settings/panel/conduit/, likewise.

Reviewers: Avish, btrahan, wotte

Reviewed By: btrahan

CC: aran

Differential Revision: https://secure.phabricator.com/D7819